|Budget Amount *help
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
Active oxygen, such as superoxide anion, play an important role in bacteria killing of neutrophils. NADPH oxidase, which produces superoxide anion, consists of cytosolic p47-phox, p67-phox, p21-rac proteins, and membranous cytochrome b558. Previously, we discovered a new low molecular weight activation enhancing factor (LMWAF) for NADPH oxidase in neutrophil cytosol. In this study, we showed that LMWAF also existed in brain, and we compared the characteristics of brain and neutrophil LMWAF.
Brain LMWAF enhanced oxidase activation even in the presence of sufficient amount of well-known LMWAFs, FAD,GTPrS,and Diacylglycerol. This indicates that brain LMWAF is different from well-konwn LMWAFs and acts via different mechanism. However, brain LMWAF seems to be similar to neutrophil LMWAF.because brain LMWAF have no additional effect on neutrophil's enhancement. Activity of LMWAF in neutrophil cytosol increased depending on the strength of sonication to prepare cytosol and membrane fractions. It is suggested that LMWAF associates with high molecular weight factor in cytosol and dissociates from it by the sonication.
On the other hand, we have reported that phosphorylation of p47-phox is important for NADPH oxidase activation, and oxidase activity was controlled by phosphorylation/dephosphorylation status of p47-phox. In this study, we investigated the relation between the phosphorylation of p47-phox and the oxidase activity in more detail. The results indicate that NADPH oxidase is not simply activated by the phosphorylation of p47-phox, reversely, the oxidase is suppressed by hyperphosphorylation or phosphorylation of other phosphorylation sites.
Active oxygen production in neutrophils is controlled by several mechanisms, and they may vest in neutrophils with multiple responsiveness to the various urgent situations.